1. Field of the Invention
This invention relates to a concrete mixer and more particularly to a horizontal drum concrete batch mixer.
2. Description of Related Art
Historically, concrete has been mixed in many types of revolving drum mixers. Such mixers are powered either with gasoline engines or electrical motors. The drums normally are rotated in a single direction at a constant speed. Discharge from the mixer is sometimes accomplished by tilting a chute into the drum's interior. Such concrete mixers usually utilize a horizontally disposed and rotatably mounted mixing drum. Such horizontal drum mixers are limited in production capacity due to the excessive time required for the discharge of the mixed concrete therefrom.
As mixer and production capacity requirements have steadily increased, the trend in the industry has been to resort to a tilting type mixer configuration. High capacity tilting mixers have been the accepted design in the concrete industry for many years with the chief advantage being high production capacity due to the fast discharge rate as the mixer body is tilted toward its cone-shaped discharge end Such tilting mixers, however, are less portable and require substantial foundations to prevent overturning of the mixer as the mixer tilts beyond the supporting framework during discharge.
In portable applications, tilting mixers are at a further disadvantage due to their physical size. For example, in some tilting mixers, the discharge cone must be removed for transport to come within highway width limits. Further, the weight, power requirements, and cost of tilting mixers is greatly increased by the necessary addition of the powered tilting mechanism.